Type your question here!

Saturday, September 16, 2017

University of Nevada Cooperative Extension and the South Valley
Rose Society are collaborating and offering educational meetings throughout the
fall. On Thursday, Sept. 28 at 7 p.m. at our Lifelong Learning Center located
at 8050 Paradise Road, Las Vegas, Nev. (I-215 and Windmill Lane). Find out how to start roses from cuttings at this
free, open to the public, workshop.

Hume has a been a member of the American Rose Society (ARS)
since 1982 and a proud holder of a Life Subscription To ARS. Hume was the President
of South Valley Rose Society. She also served as President of Las
Vegas Valley Rose Society twice and first Vice President for 8 years. Hume has
successfully started roses from cuttings for over 10 years. Her percentage
of success in cuttings survival rate is over 90 percent. Hume
likes everything roses: rose people, rose exhibiting, rose books
and rose clothes.

All
educational meetings are held at 7 p.m. at the Lifelong Learning Center located
at 8050 Paradise Road, Las Vegas, Nev. (I-215 and Windmill Lane). For more
information, please call the Master Gardener Help Desk at 702-257-5555 or email
lvmastergardeners@unce.unr.edu.

Sunday, September 10, 2017

This comment was sent to me about growing lemon successfully in the Mojave Desert. From the looks of the fruit I think it is a Lisbon lemon, one of the true lemons unlike Meyer which is not a true lemon and much more hardy to winter cold than Lisbon. This tree is located in the NW part of the Las Vegas Valley, north of Grand Teton.

We planted our lemon tree in Fall of 2006 as a
24" box. It has grown to a height of 20 feet plus and has produced a major
crop every year but one. In that year we had a major freeze and we removed over
a hundred pounds of frozen fruit, we have had a full crop every year since.

Our tree is positioned in
an alcove that faces south.

We wrap the tree every
winter on the south face of the tree and leave a vent at the top so the heat
build up from the wrap during the day can vent.

We hand fertilize on four
sides of the tree in most years and have general fertilizer tank that we fill
twice a year in the spring and fall.

Q.I've added some new shrubs under pine trees and they
are all doing poorly. I've read that pine needles are acidic and can change the
pH balance in the soil. I've also read that's not true. Could the pine needles
be affecting the new shrubs?

A.I am on the side of "it doesn't make much
difference". Yes, pine needles contain a lot of resin and they don't break
down quickly. But having them on the surface of the soil, or mixed into the soil
at about 5% of the soil volume, makes no difference at all!

Using pine needles like these from a Chir pine problem in desert soils when used as a surface mulch. If they are mixed into the soil, try to keep the amount less than 10% by volume. They decompose much faster when they are shredded. They help lower soil pH which is very important in desert soils.

Besides the resin, there is some slight lowering of pH (more
acidic) which in our soils is actually helpful. Hopefully you amended the soil
under pine trees with compost at the time of planting.

Digging a hole large enough for plants under pine trees
can be difficult because of the roots of the pine. Don’t be afraid to cut pine
roots when planting. Allow these cut roots to heal 24 to 48 hours before they
are buried in the soil again.

Look closely at the amount of light these plants are
receiving. Some plants grow nicely with 50% or more sunlight available to them.
Others need much more than this for good growth. As an example, Bermudagrass
can handle about 10% shade while tall fescue can handle nearly 50% shade.

Generally speaking, flowering plants need lots of light
compared to non-flowering plants. Signs of a lack in light can be a general
failure of the plants to thrive, leaf drop and a general thinning of the canopy,
and leaf yellowing. You may have to remove some of the lower limbs to allow
enough sunlight to the plants growing beneath the canopy.

Q. I have lots of weeds in
my lawn and the more I pull it out, it seems the more comes up! Besides
spraying with Roundup, what can I do?

A.The density of a lawn prevents weed problems. Weeds
invade your lawn because the lawn is not thick enough to "choke out"
existing weeds and prevent weeds from getting established.

A lack of density can be from too much shade, mowing the
lawn too short, disease or insect problems, not applying fertilizer often
enough or a lack of water.

Mow at least once a week. Mow tall fescue at a 2 inch
height above the soil. Never mow or "weed whack" tall fescue below 1
1/2 inches in height. This opens the lawn up for weed invasion.

Line trimmers used 2 edge lawns like this one managed by a landscape company cuts fescue too short which encourages invasion by Bermuda grass.

Bermudagrass lawns need full sunlight. Tall fescue lawns
should receive no less than 75% of full sunlight. Some people will say 50% but
I think that’s right on the edge. If it's less than 75% sunlight, remove or
decrease the amount of shade by pruning trees causing this shade.

How do you know the percentage of shade? Look at the
ground under the canopy at noon. The amount of shade is easier to estimate
during this time of day. If it’s 100% shade, open up the canopy with a few
pruning cuts that remove entire limbs from the trunk.

By looking at the ground beneath the tree you can estimate the percent shade.The percent shade under the canopy of this tree, not out the open, is maybe 25%, not enough for fescue to grow well.

Lightly fertilize lawns every 4 – 8 weeks when using quick
release mineral fertilizers. In most bags of inexpensive fertilizer, half of
the rate listed on the bag is enough to apply if you are using a mulching
mower.

Apply quick release fertilizers to fescue lawns 4 times
during the year during the major holidays of Valentine’s Day, Memorial Day, Labor
Day and Thanksgiving. Bermudagrass lawns are fertilized during the heat of the
summer but ending by September 1 if overseeding.

Slow release fertilizers are applied in larger amounts
but less often. They are expensive but they save labor. Make sure a fertilizer
application is applied at Thanksgiving if you want to maintain a green fescue
lawn through the winter.

Osmocote is a well known slow release fertilizer

Make sure lawns are irrigated overhead with “head to head
coverage” from sprinklers. This means that water from sprinklers are thrown far
enough to hit the neighboring sprinkler.

Make sure water pressure to sprinklers is not above or
below the range recommended for the nozzles of your sprinklers. Inappropriate
water pressures cause poor coverage of the lawn.

Avoid disease problems
by irrigating during the early morning hours just before sunrise.

Q. When is the proper time
to prune Meyer lemon? We have a large crop of lemons ripening now. The tree is
very dense and the fruit is on the outside perimeter of the tree. Last time I
pruned it in January or February and had no fruit that year. Can I do it now in
September or wait until October or November?

A. Meyer lemon, not a true
lemon, is usually harvested in December or possibly as late as early January.
But do not harvest it later than this. Harvesting time is your signal for
pruning. Waiting longer than this can possibly remove fruit during that growing
season.

Meyer lemon grown in protected culture in Afghanistan.

Prune immediately after harvest. Do not delay harvesting
the fruit or this can confuse the tree about when to flower again and may affect
the quality of the fruit.

It is strange your Meyer lemons are ripening now. Fruit
can take nearly 11 months to mature. Harvest the fruit when sugar in the fruit
reaches a minimum of 10 Brix. Brix is measured with a refractometer. It’s
handier to taste the fruit and see if it’s ready. When it is sweet, harvest it.

Refractometer

Citrus is not pruned much, only to remove crossed or
broken branches. You could remove a few limbs too close together which would allow
more light inside the tree canopy. Probably removing 3 or 4 limbs would be
enough.

Citrus response to pruning cuts

Make sure the pruning saw or loppers has been sanitized
and sharpened before pruning. Do not leave any stubs unless you want regrowth
from them.

Q. I laid tall fescue sod
earlier this year in my backyard. It has been great until about a week ago when
half the yard turned yellow! I use an inground sprinkler system and water 7
days a week for 3 minutes at 7 AM, 11 AM and 3 PM. The soil is moist about 4
inches down.

A.Why are you still watering 3 times a day for 3 minutes
each time? This might be okay for the first couple of weeks after laying the
sod but those times should change.

Your irrigation schedule during the heat of the summer
should be once a day for a total of about 12 to 15 minutes if you are using
pop-up sprinklers. The actual number of minutes depends on the precipitation
rate and spacing of the sprinklers.

These are determined by the type of nozzle, pressure used
and irrigation design. Poorly designed irrigation systems require more minutes
than well-designed systems.

With head to head coverage the water from a sprinkler is thrown far enough to reach the neighboring sprinklers

The best time to water a lawn are the hours just before
sunrise when the wind is calm. If you can't water for 12 to 15 minutes all at
once because of puddling or water runoff, break your irrigation times into
smaller increments, each about one hour apart.

Aerifiers punch holes in a lawn for better water and air movement to grass roots.

Get all of the water the lawn needs for that day into the
soil during the early morning hours. The lawn can "drink" from this reservoir
of soil water until the next irrigation.

Lawn grass root development after aerifying

Aerify the lawn with a
core aerator 2 or 3 times a year until you can water the lawn for longer and
longer periods of time without puddling or runoff. After aerating a few times,
you should be able to easily wet the soil to a depth of 8 to 10 inches each
time you irrigate.

Readers picture of the remaining grass in his long

Follow-up question:

Q. laid the sod in April and
was worried that it was a bit too hot but it took root and was flourishing.
The sod is a raised bed on 4 inches of topsoil from Star nursery over the
local clay which I tilled. I dug a "core" of grass that
recently died and had some living grass as well. The living grass is
still rooted strong but the dead grass pulls out very easily. I don't see
any bugs. I was unaware of the proper watering and will adjust
accordingly. Do you think there's any saving this lawn or do I
need to re-sod? If so, I'm assuming mid-October is preferred for Tall Fescue.
Also, for the first few months I was getting a lot of mushrooms. I
no longer get them. Could this be indicative of fungus or disease?
Again, thank you so much for your help.

Mushrooms appearing in a lawn is a signal that something in the lawn has not finished decomposing. Mushrooms are decomposers.

A. The mushrooms are from decomposing
woodchips, probably in the soil mix. It's not a huge problem and it doesn't
mean there is a disease going on. When the wood chips are exhausted, the
mushrooms will stop.

I would suggest about October 1 to rake
or lightly vertically mow, also called a dethatcher, and rough up the surface
of the soil. Seed a blend of tall fescue varieties at a rate of about 8 to 10
pounds per thousand square feet. Fertilize it and water it in. Then cover the
seed with a top dressing about one quarter of an inch deep using a manure
spreader. If it's cool enough, you could use steer manure and a spreader.

Dethatchers are sometimes called vertical mowers because the small blades that rotate on the shaft are spun vertically rather than horizontally as in a rotary mower.You can adjust the depth of the vertical cut so the soil is disturbed as much or as little as you want.These are vertically spun blades can cut grooves for better soil and seed contact.

I think you're going to have to reseed or
re-sod the area and I think seeding is a better option for you. Your irrigation
times after the seed germinates I don't think you'll have a problem.

Welcome to Xtremehorticulture

Home. My home base is Las Vegas, Nevada, in the Eastern Mojave Desert. This blog focuses on horticulture in Deserts.

Me. Desert Horticulture is very different from horticulture in wet climates. Very few people talk about it. This blog focuses on it. My experience in horticulture span over 50 years; time as an applied academic and now working as a consultant. This blog shares my experience and advice in Desert Horticulture. Work in Northern, East and Southern Africa, Western and Central Asia and the Middle East have expanded my views on Desert Horticulture.

Questions. I reply to questions sent to me as quickly as possible. Please include pictures. It helps. Unless questions are confidential, I post them on this blog if they add new information.